[Patency of surgically revised ePTFE-dialysis access grafts]. / Ist die chirurgische Revision von ePTFE-Dialyseshunts gerechtfertigt?

UNLABELLED: Native av-fistulas are the access of first choice for long-term hemodialysis. However, a large number of patients require an alternative vascular access, e. g. ePTFE grafts. Patency of ePTFE grafts is inferior to that of native av-fistulas. PURPOSE: To analyse the effectiveness of surgical revisions of occluded straight ePTFE dialysis access grafts. METHODS: Retrospective review of all upper arm dialysis access procedures from 1/94 to 8/99. RESULTS: Redo surgery was performed in 67 patients. Av-fistula dysfunction was caused by venous anastomotic stenoses (22 %), outflow occlusion (9 %), arterial anastomotic stenoses/inflow occlusion (12 %), and intragraft stenoses (6 %). 9 grafts had to be revised due to infection or perigraft hematoma (14 %). In 37 % the cause of graft occlusion could not be identified. Neither the cause of occlusion nor the type of treatment correlated with patency after revision. 6- and 12-months primary patency after surgery were 29 % and 11 %. 59 shunts required up to 12 revisions to maintain patency. Thus, secondary 1 yr-patency after revision was 29 %. CONCLUSION: Patency after redo surgery is disappointing. However, with repeated procedures ePTFE grafts remain open > 1 year in 29 % of the patients.

[Non-neoplastic hypertrophic osteoarthropathy due to infected aortic prosthesis. Diagnostic imaging aspects]. / Nichtneoplastische hypertrophische Osteoarthropathie auf dem Boden einer infizierten Aortenprothese. Aspekte der bildgebenden Diagnostik.

Secondary hypertrophic osteoarthropathy of the legs is a rare complication of arterial graft surgery. The syndrome is composed of arthralgias, clubbing of the toes and periostosis of the long bones and is usually associated with an infected aortic prosthesis. Often a CT-guided biopsy is performed in order to identify the graft as the primary focus. In addition to the lamellar periostosis demonstrable by conventional radiographs, a vast edema of the bone marrow and surrounding soft tissue is disclosed by MRI. Imaging promotes the early surgical reintervention.

Prospective study on the complication rate of carotid surgery.

BACKGROUND: Randomized trials of carotid endarterectomy for high-grade stenosis have shown a benefit for surgery under the condition of low perioperative complication rates. Concerns have been expressed that the complication rates of carotid surgery are higher in everyday practice and may vary considerably between centers. We prospectively established the complication rate for carotid surgery in a single institution. DESIGN: Prospective 2-year study. All patients received pre- and postoperative neurological evaluation. Laboratory tests included pre- and postoperative brain imaging, intracranial and neck vessel sonography, conventional angiography, magnetic resonance angiography, and intraoperative monitoring. PARTICIPANTS: 108 consecutive patients: 54 symptomatic patients fulfilling the inclusion criteria of the European Carotid Surgery Trial (ECST) and 54 asymptomatic patients fulfilling the inclusion criteria of the North American Trial on Asymptomatic Stenoses (ACAS). SETTING: Single academic center with a high volume of carotid endarterectomies (>50 per year). Participating center in ECST. MAIN OUTCOME MEASURES: Stroke or death as defined in the randomized trials. RESULTS: The overall complication rate was 8.3% (95% CI 4.1-15.6%). Complications were more frequent in patients with symptomatic stenosis (11.1%, CI 4.6-23.3%) than in asymptomatic cases (5.6%, CI 1.5-16.4%). Three patients died (2 strokes, 1 myocardial infarction). Disabling strokes were found in 2 patients (Rankin scale scores 3 and 4). Nondisabling strokes (Rankin scale score 1 and 2) occurred in 4 patients. The complication rates for symptomatic and asymptomatic patients were higher than the ones reported in the randomized trials, but 95% confidence intervals showed that the differences were not statistically significant. The point estimates of complication rates still supported a benefit of surgery for patients with symptomatic stenosis, but denied a positive effect of endarterectomy for patients with asymptomatic stenosis. CONCLUSION: In this center, a beneficial effect of carotid surgery for asymptomatic stenoses cannot be safely assumed.

Hemoglobin oxygenation of venous-perfused forearm flaps.

To understand how venous flaps function we investigated whether blood flowing via the venous network reaches the capillaries of the skin. While measuring spectrophotometrically intracapillary hemoglobin oxygenation of fasciocutaneous forearm flaps in 12 patients, flap perfusion was changed by manipulating nutrient vessels. Conventionally perfused radial forearm flaps had an intracapillary hemoglobin oxygenation of 51% to 74% but decreased to 6.9% to 12.2% within 90 to 120 minutes after arterial occlusion and perfusion only from the cephalic vein entering the flap cranially (type I venous flap). Radial forearm flaps without any vascular connection showed no oxygenated hemoglobin after 180 to 240 minutes in the capillary network. After microsurgical vein anastomosis and release of the blood flow only via the cephalic or accompanying veins, hemoglobin oxygenation returned immediately to about 10%. We conclude from our results that there is actual capillary perfusion, albeit very slight, in type I venous forearm island flaps.

[Color-coded duplex sonography and ultrasound contrast medium in the study of peripheral arteries--initial clinical experiences]. / Farbkodierte Duplexsonographie und Ultraschallkontrastmittel zur Untersuchung peripherer Arterien--Erste klinische Erfahrungen.

Ultrasound contrast agents (US-CA) amplify reflected sound waves. Most substances used as contrast agents are destroyed when passing the lungs. SH U 508 is a new US-CA that can pass the lungs without impairment after peripheral intravenous application. In a clinical trial of this US-CA, we investigated its effect on the visualization of blood movement in peripheral arteries by color-coded Duplex sonography (CCDS). The leg arteries of 20 patients with severe chronic arterial occlusion were examined by CCDS (QAD I and Platinum) after i.v. application of the US-CA. After passage of the pulmonary capillaries, the US-CA amplified blood flow signals in the arterial system in a dose-dependent manner with both systems used. Undesired side-effects were not observed. The amplification produced by appropriate concentrations of the US-CA markedly improved the visualization of blood movement. Further studies are required to determine the optimal dosage and application technique as well as the indication for using this US-CA.

[Results of surgical therapy of esophageal carcinoma]. / Ergebnisse der chirurgischen Therapie des Osophaguskarzinoms.

In esophageal cancer radical resection of the affected segment is the therapy of choice for tumours confined to the wall. Palliative resection at advanced tumour stages does not improve survival and markedly increases mortality. Neither chemotherapy nor radiation influence the survival rates. Tumours of the middle third are resected by the thoracic approach, while tumours of the lower third may be resected by blunt dissection. The best reconstruction is achieved by interposition of the stomach. The jejunum or colon may be interposed in the case of a previous gastric resection. In our department, postoperative mortality was 8.8%, corresponding to 137 operations with stomach interposition. The 5 year survival rate was 39.9% in stage I and II and 10.6% in stage III and IV. Complications and mortality were markedly increased in advanced tumour stages. The thoracic approach was not correlated with higher postoperative lethality.